Many applications require fluids to be moved from one structure to another. A liquid or a gas, for example, may be transferred from a storage container to the interior of a machine, or from the interior of a machine to a storage container. In certain applications, fluids may be required to be transferred without leakage to avoid loss of the fluid into the atmosphere and to reduce the introduction of impurities into the contained fluid. Couplers are often used to facilitate this fluid transfer.